Process of discharging indigo-dyed wool.



UNITED STATES PATENT OFFICE.

WILHELM BERNS, OF LUDWIGSHAFEN, GERMANY, ASSIGNOR TO BADISCHE ANILIN d: SODA FABRIK, OF- LUDWIGSHAFEN, GERMANY, A CORPORA-- TION OF BADEN.

l ROCESS OF DISCHARGING lNDlGO-DYED W OOL.

SPECIFICATION forming part of Letters Patent No. 690,347, dated December 31, 1901.

Application filed January 23 1901.

To all whom, it may concern:

Be it known that I, WILI-IELM BERNS, doctor of philosophy and chemist, a subject of the King of Prussia, German Emperor, residing at Ludwigshafen-on-the-Rhine, in the Kingdom of Bavaria, Germany, haveinvented new and usefullmprovements in Processes of Discharging Indigo-Dyed Wool, of which the following is a specification.

The processes for producing white or colored discharge eifects on indigo-dyed wool at present. known are, so far as I am aware, more or less unsatisfactory. For instance, by attempting to apply to wool the chromate discharge process as used for indigo-dyed cotton it is found impossible to obtain even impure whites, as hardly any destruction of the indigo on the parts printed is efiected, and the colored eitects obtained by this method are on this account insufficiently brilliant. I have found that by the addition of certain steps to the known discharging process exceedingly pure white and colored discharge efiects on indigo-dyed wool can be produced; 2 5 and my invention consists in the addition of these steps to and in the combination of these steps with the known discharging process. The said steps are, first, steaming the goods after having printed them with a discharg- 3o ing composition, and, second, treating the goods with a bleaching agentsuch a sulfurous acid, hydrogen, peroxid, potassium percarbonate, and the like after having discharged them.

The following examples will serve to further illustrate the nature of this invention and the manner of carrying it into practical efiect; but the invention is not confined to the examples. The parts are by weight.

Emample 1-W'hite discharge effect on ind igo-dyed w00l.Print indigo-dyed woolen material with a discharge composed of three hundred and fifty (350) parts of tragacanthwater, six (6) per cent; four hundred (400) 45 parts of gum-Water (1:1,) one hundred and twenty-five (125) parts of water, and three hundred (300) parts of sodium bichromate,

, (powder.) Steam the goods for five (5) min- Serial No. 44,455. (N specimens.)

utes in a Mather-Flatt apparatus and pass them for about twenty (20) secondsat atemperature of fifty-five to fifty-seven (57) degrees centigrade through a bath containing fifty (50.) grams of oxalic acid, fifty (50) grams of sulfuric acid (containing ninety-five (95) per cent. H 80 in one (1) liter of solution, and then leave for several hours in a bleaching-bath made up of five hundred (500) parts of hydrogen peroxid, (containing about two (2) to three (3) per cent. H O five hundred (500) parts of Water, and fifteen (15) parts of ammonia solution, (containing about twenty (20) per cent. NH Wash and dry. In place of hydrogen peroxid aqueous sulfurous acid, bisulfite-of-soda solution, gaseous sulfurous acid, or potassium percarbonate can be employed.

Example 2-Red discharge efi eot 0n indigo- (Zyed 'w00Z.Print the indigo-dyed wool with a mixture of three hundred (300) parts tragacanth- Water, six (6) per cent; three hundred (300) parts of gum-water (121;) six hundred and ten (610) parts of water, sixty (60) parts of indulin scarlet, and three hundred (300) parts of powdered sodium bichromate. Steam the goods. Pass them through the discharging -bath, as in Example 1, and bleach them with an alkaline solution of hydrogen peroxid or with aqueous sulfurous acid of four (4) degrees Baum or with sodium-bisulfite solution of five (5) degrees Baum, or with an atmosphere of gaseous sulfurous acid.

In place of indulin scarlet methylene blue B extra can be used to produce blue effects, azoflavin 3G. for greenish yellow effects, azoflavin 3H. for reddish-yellow eifects, and rhodamin extra for carmine effects, while of course, if desired, multicolored effects or colored eifects in combination with white effects can be produced on the same goods.

Now What I claim is 1. The process for producing discharge effects on indigo-dyed wool which consists in printing the goods with a discharging-paste, steaming them and bleaching them when discharged with a suitable bleaching agent, sub- 95 stautially as hereinbefore described.

In testimony whereof I have hereunto set 2. The process for producing discharge ef- I my hand in the presence of two subscribing fects on indigo-dyed wool which consists in printing the goods with adischarging-paste, Witnesses. containing a suitable coloring-matter, steam WILHELM BERNS. in g them and bleaching them when discharged Witnesses:

OSCAR BALLY, JOHN L. HEINKE.

with a suitable bleaching agent, substan tially as hereinbefore described. 

